The invention relates to a harvesting machine, in particular a combine harvester, having a dividing for dividing a granular stream of material from the stream of material of remaining plant parts, a separating device connected downstream of the dividing device, and a revolving conveying unit having conveying tines being provided to convey the stream of the material from the dividing device to the separating device.
Conventional combine harvesters are generally provided with a threshing unit as a dividing device for dividing the grains from the ears of cereal, and therefore also from the straw, with a separating device being connected downstream thereof. In this separating device, (conventionally designed as shakers), the stream of grain material is divided from the stream of straw material.
Apart from so-called surface shakers, in which a shaking element extends over the entire working width of the separating device, use is also made of so-called tray-type shakers with which the shaking surface has been divided up, so that individual trays are arranged next to one another over the working width in accordance with a flat separating device. The individual shaker trays can execute different shaking movements, under the control of a crankshaft, for example.
In order to conduct the stream of material from the dividing device to the separating device, use is made of various conveying devices. Use is frequently made in this case of so-called conveying drums which operate either in an overshot manner or an undershot manner and conduct the material from the dividing device to the separating device using conveying tines protruding from the circumferential surface of the conveying drum. In many embodiments of a conveying drum of this type, the conveying tines in this case are fixed such that they can move with respect to the conveying drum and eccentrically with respect to the axis of the conveying drum, on a crankshaft, for example. Conveying units of this type are described, for example, in the publications EP 86 28 48, EP 86 28 49 and EP 86 28 50.
Experience has shown that with such controlled conveying tines, there is the not inconsiderable risk of the rotating conveying drum not completely discharging the material, with the result that the straw becomes jammed on the circumferential surface of the drum and is carried along over the entire circumference of the drum. Within a very short period this leads to a layer of straw building up on the circumferential surface of the drum, resulting in the combine harvester stopping. This process is also referred to as winding.
In contrast, the invention has the object of proposing a harvesting machine, in particular a combine harvester, in whose conveying device satisfactory discharging of material takes place in order to supply the separating device.
Taking harvesting machines of the type mentioned in the introduction as the starting point, this object is achieved by the characterizing feature in that at least one cleaning element for cleaning the material away from the free end of the conveying tines is provided.
Advantageous designs and developments of the invention are possible by means of the measures mentioned and described herein.
Accordingly, a harvesting machine according to the invention is distinguished in that at least one cleaning element for cleaning the material being conveyed away from the free ends of the conveying tines is provided.
In the case of conveying drums of the abovementioned type, it turns out that the winding, i.e. in the case of a combine harvester, the buildup of a layer of straw on the conveying unit, is essentially caused by the conveying tines. Above all, the material being conveyed, for example straw, is not completely detached from the free ends of the conveying tines at the right time. An additional cleaning element according to the invention assists the detaching of the material from the conveying tines, so that the winding on of material in the form of stem or stalks can be avoided. A cleaning element of this type can be used not only in conjunction with the abovementioned conveying drums, but it can also be used in the case of other conveying units, for example in the case of reel-shaped conveying units or the like.
However, a cleaning element according to the invention is preferably used on a conveying drum having conveying tines, in particular on a conveying drum having movable, controlled conveying tines. As mentioned above, without a cleaning element in this type of conveying unit the material in the form of stems or stalks frequently becomes jammed between the circumferential surface of the drum and the conveying tines when the tines enter into the circumferential surface of the drum, with the result that the abovementioned problem occurs with increasing frequency. As long as the conveying tines has [sic], however, been cleaned beforehand, this jamming is no longer possible.
In a particularly advantageous embodiment, in conjunction with controlled conveying tines mounted on a conveying drum, the invention comprises mounting the cleaning elements on the conveying drum itself, so that the cleaning element rotates together with the conveying drum. By this means, elaborate structural measures in the region of the conveying drum above the separating device are avoided. The invention can be realized by a comparatively uncomplicated modification of the conveying drum.
A cleaning element of this type preferably includes a cleaning strip which extends over the length of the conveying drum and is provided with recesses for the conveying tines. During operation of the conveying unit, the conveying tines move in these recesses. Whereas the free ends of the conveying tines always have to be guided in the circumferential surface of the conveying drum, so that their movement is controlled, and therefore cannot quite dip into the conveying drum, the conveying tines can pass over the cleaning strip completely, so that the material being conveyed is cleaned off completely and can neither become jammed between the conveying tines and the cleaning element nor between the conveying tines and the circumferential surface of the conveying drum.
In an advantageous development of the invention, in addition to the conveying tines, further conveying elements are mounted on the conveying drum. In the rear region of the conveying drum, the conveying tines act in an upward direction, as a result of which the stem- or stalk-like stream of material is lifted up. By means of additional conveying elements, which may, for example, be mounted rigidly on the circumferential surface of the conveying drum, loosening up of the stream of material as it is being conveyed, and therefore a better action over the entire length of the separating device with a more uniform distribution of the material can be achieved. The efficiency of the separating device can therefore be increased.
An additional conveying element of this type advantageously includes a conveying strip protruding obliquely from the circumferential surface area of the conveying drum. A conveying strip of this type is, because the conveying strip is arranged obliquely and not radially with respect to the cylindrical circumferential surface area, able to convey the lifted-up stream of material away from the conveying drum in a loosened up manner.
The conveying strip is advantageously connected to the cleaning strip. This results in only one further component being necessary in order to attach both the cleaning element and the conveying element to the conveying drum. The manufacturing outlay is reduced as a result.
The conveying strip is preferably connected continuously to the cleaning strip. This results in a type of hood-shaped design of the cleaning element in conjunction with the conveying strip. The conveying strip therefore at the same time prevents material which is to be cleaned off from being able to get into the region between the cleaning strip and the circumferential surface of the drum.
In a preferred development of the invention, the recesses in the cleaning strip are designed as open slots. This especially facilitates the fitting of the cleaning strip which, as a result, does not need to be placed onto the conveying tines and, in addition, enables the conveying tines to have the freedom of movement necessary because of the crank control in the circumferential direction of the circumferential surface area of the conveying drum.
The cleaning element is advantageously fastened, for example riveted, screwed or welded, to the circumferential surface area both via the cleaning strip and via the conveying strip. It is recommended for this to make corresponding bevels with which the cleaning element rests in a planar manner on the circumferential surface area of the conveying drum, and at which the welding can be undertaken.
In a particularly advantageous embodiment of the invention, the cleaning element including the conveying strip and the bevels provided for the fastening are bent from sheet metal. This makes cost-effective manufacturing possible.
In a further advantageous embodiment of the invention, supporting elements are provided under the cleaning element. These supporting elements, which may, for example, be designed such that they protrude from the circumferential surface area of the conveying drum in the region of the oblique conveying strip, support the cleaning element, so that the use of a correspondingly weaker material for the production of the cleaning element is possible. In addition, the cleaning elements may, for example, also be connected to the conveying drum on such supporting elements. Fastening by means of welding, screwing, riveting, etc. is also conceivable here.
In a particular embodiment of the invention, at least two conveying units as described are used for distributing the stream of material to the separating device, as a result of which uniform supplying of material with repeated loosening up remains ensured even in the case of relatively long separating devices.
It has furthermore proven advantageous if the separating device below the conveying unit is adapted to the shape of the conveying unit. In addition to good conveying of the stream of material, this at the same time reproduces a guiding function for the stream of material. By this means, in particular in conjunction with a conveying drum which has the above-described, additional conveying elements, the distribution of material can be further improved. To a certain extent, in interaction with the additional conveying elements a type of throwing-off ramp for the material being conveyed is produced.
This adaptation of the separating device can also be carried out in the case of a so-called tray-type shaker, as mentioned above. In this case, the individual shaker trays moving with a regular shaking movement up and down below the conveying unit, are adapted to the shape of the conveying drum.
The adaptation of the shape of the shaker trays to the shape of the conveying drum advantageously also includes a corresponding design of the lateral housing walls of the individual shaker trays. These walls, which are regularly provided with sawtooth-shaped designs which permit only one stream of material in the conveying direction, are, in the development described, provided with rounded cutouts, so that a shaker tray of this type can be moved comparatively closely up to the corresponding conveying drum.
It is furthermore advantageous if additional, upper conveying means are assigned to the conveying unit according to the invention or to the conveying units according to the invention. These upper, additional conveying means in particular contain the stream of material discharged upward by the conveying unit or the conveying units, and can convert the upward movement of the stream of material in this region into a movement in the direction of the separating device. This can also result in a more uniform distribution of material on the separating device.
Different measures are suitable as the upper conveying means. For example, rods which are arranged next to one another in the manner of a rake and have a crank drive may be provided, which rods are optionally provided with corresponding, additional carrier elements for conveying the impacting stream of material in the direction of the separating device. Examples of suitable carrier elements include tine- or step-shaped designs. Other conceivable embodiments of an upper conveying means of this type comprise, for example, planar arrangements with or without additional conveying elements. Revolving devices, for example in the form of one or more drums or of a belt conveyor with or without corresponding, additional conveying elements are also conceivable at this point.
An exemplary embodiment of the invention is illustrated in the drawings and is explained below in more detail with reference to the figures.